SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c1dcc45e8bebbc44b64705585536449c9e3fe9a691f52aa84eafbe3465c29f2' 
  AND token = 'wYVE75/E+RJ1v5L+cL8QhtrvZUhNogZ1MYXF6wV4jqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}